by the way, how big is the release of a dan brown thriller? he is ranked, his books, as the most read books in the world, up there with books like the bible. >> the bible? wow! >> every tweet is a dot on that board. some people are starting to talk about florence. ey think they can make out that there. >> someone on twitter or facebook has correctly guessed the title of the book. maybe dan brown himself. >> inside information there. >> before we get to this mystery, let's check in with al roker in chicago this morning. good morning again. >> thanks so much. we have friends here from the chicago polar plunge, to benefit special olympics chicago. we even have a polar bear. only eaten three people here. that worked out pretty well. let's see what we've got for you as far as today is concerned. snow showers in the northern plains. we've got a winter weather advisory stretching in to dallas, morning snow. plenty of sunshine in the southwest. but it's still awfully chilly. rain in the midatlantic states. tomorrow we expect to see more heavy rain alo